The present invention relates to a new and useful monitoring device, and particularly to a wireline extensometer that is particularly useful in monitoring ground movement, e.g. slopes in an open pit mine environment.
In an open pit mine environment, it is useful to accurately measure movement of a slope mass, in order to identify slope instability, and develop engineering plans to accommodate slope movement or provide for a remediation. In the applicants' experience there is a need for an extensometer that is sensitive to slope mass movement, while minimizing the chance of reporting data that suggest slope movement where the slope mass has not moved to an undesirable extent. In the applicants' experience, it is desirable to measure slope movement at relatively slow rates as well as rapid rates. In addition, in the applicants' experience, it is important to have an extensometer that, as part of a stand alone monitoring system, can measure slope mass movements continuously, and in a manner that can be efficiently and effectively communicated to the responsible personnel.